1. Field of the Invention
The present invention relates generally to apparatus used during performance of surgical procedures and, more particularly, to apparatus for securing a limb of a patient while medical or surgical procedures are performed on the patient.
2. Description of the Prior Art
Often it is necessary to secure a limb of a patient in a desired position during the performance of many medical and surgical procedures. For example, current trends in orthopedic surgery show increasing use of "keyhole" type surgical procedures for performing joint surgery. It is common during the performance of keyhole, including arthroscopic, surgical procedures to insert viewing and cutting instruments into the joint through small puncture wounds formed in the skin. Often, it is necessary to fix the position of the limb to facilitate manipulation of the joint to properly position the viewer or the cutter within the joint.
Conventional limb restraints employ a type of clamp which bears some resemblance to an ordinary clamp. The clamp exerts pressure on the limb at, essentially, two points on opposing sides of the limb. Because the restraint contacts the limb at only two locations, the force exerted by the restraint at those locations must be relatively high to permit proper positioning of the limb. Accordingly, pinching, sore spots and sensory loss can be experienced by a limb when constrained by a conventional limb restraint. Further, the degree to which a limb can be constrained by a conventional restraint is not as great as can be attained through use of a restraint that makes contact with the limb at more than two points. U.S. Pat. Nos. 4,181,297 and 4,252,306 show clamp restraints.
Performing arthroscopic surgery using the supra patellar approach involves insertion of a viewing instrument and a cutting instrument through a puncture wound formed just to the thigh side of the kneecap. During performance of arthroscopic knee surgery using the supra patellar approach, a limb restraint should be used to fix the position of the thigh. Many conventional limb restraints are so thick or bulky that they impede the manipulations of the viewer and cutter that must be achieved to employ the supra patellar approach.
U.S. Pat. No. 4,299,213, issued to James T. Violet, shows a leg stabilizer (the "Violet stabilizer") which employs an inflatable restraint. Use of the Violet stabilizer presents several problems. Several of the problems are due to the use of an inflatable restraint, which presents the risk that either a puncture of the restraint or a failure of the source of air pressure will render the Violet stabilizer virtually useless. Further, the forces applied to the lower leg as the surgeon flexes the lower leg during the performance of arthroscopic knee surgery will cause the restrained portion of the leg to shift within the inflatable restraint.
Accordingly, there exists a need for a limb restraint that provides a higher degree of limb fixation than that achieved by a conventional restraint that clamps the limb at two points, and that causes less physiological damage to the limb than that caused by the conventional restraints. Further, there exists a need for a limb restraint that does not impede employment of the supra patellar approach to arthroscopic knee surgery.